"In addition to the financial compensation, Aetna has created what it's calling a 'best practices' document, and it's about following appropriate protocols for sharing protected health information ... with the goal of preventing this type of event from ever occurring again," Goldfein said.

"This is, as far as we can tell, the largest data breach involving HIV-related privacy."

The AIDS Law Project of Pennsylvania and its co-counsel announced the settlement on Wednesday.

'The painful irony'

"Through our outreach efforts, immediate relief program and this settlement we have worked to address the potential impact to members following this unfortunate incident," Aetna said in an emailed statement to CNN.

"In addition, we are implementing measures designed to ensure something like this does not happen again as part of our commitment to best practices in protecting sensitive health information," the statement said.

Aetna was sued in 2014 and 2015 for requiring customers to receive their HIV medications through the mail and not allowing them to pick them up in person at pharmacy stores, the latest lawsuit noted.

Those previous lawsuits were settled, and on July 28, letters were sent in the mail to inform Aetna customers that they no longer had to mail-order their HIV medications.

As it turns out, those letters were the same mailings that ended up outing customers' HIV statuses through their envelopes.

"So the painful irony here is that the notice that stemmed from a concern about HIV privacy in the mail generated the notices that disclosed people's HIV status," Goldfein said.

Through the program, Aetna offered reimbursements and payments to customers who claimed to have suffered financial hardship as a direct result of the privacy breach.

'There's no shame in having a virus'

From Los Angeles to New York, the plaintiffs' lawyers in the latest lawsuit said, they heard stories from customers who claimed to have been directly impacted by the breach.

"One woman had to leave her home after a relative moved out, and she could no longer afford the house without the benefit of the roommate's contribution," Goldfein said.

"One person reported that after the word got out that there was some homophobic vandalism to his home, and so he moved," she said. "A man told us that he brought his mail in, put it down on the counter when his family was there."

Goldfein added that Aetna customers, and all Americans, should know that they should not feel ashamed of their HIV status. Rather, a right to privacy should come with any health condition.

"There's no shame in having a virus and no shame in having HIV. ... Yet we say, 'but don't let anyone know; we must keep this completely private,' and that sometimes sends a mixed message," Goldfein said.

"I think some of the shame fuels the stigma; the stigma fuels the epidemic," she said.

"Until we can really make progress on stigma, we have to be ever mindful of people's privacy."